Research Output Prize 2022-23

Tandem solar cells enable higher efficiencies compared to single junction solar cells, and combine the advantages of different photovoltaic technologies. While perovskite/Si tandem cells exhibit the highest efficiency, solution-processed tandem devices such as perovskite/organic and perovskite/perovskite tandems have been attracting increasing interest due to their low-cost, low-temperature processing. Perovskite/organic tandems are promising in terms of stability as narrow band gap cell uses organic materials instead of Pb-Sn-based perovskite, which is susceptible to oxidation. Still, their efficiency has been significantly lower than perovskite/perovskite tandem cells. 

 

In this collaborative work involving HKU, SUSTech (Shenzhen) and NUS (Singapore), improvements have been made in the performance of wide band gap perovskite solar cell to minimise open circuit voltage losses and the design of very thin transparent conductive oxide interconnecting layer to minimize losses in the interconnecting layers. These improvements, particularly the use of conductive oxide-based interconnecting layers, have enabled the achievement of an efficiency breakthrough compared to the common approach of using metal nanocluster-based ones.

Details of the journal paper:
“Monolithic perovskite/organic tandem solar cells with 23.6% efficiency enabled by reduced voltage losses and optimized interconnecting layer”, W. Chen, Y. D. Zhu, J. W. Xiu, G. C. Chen, H. M. Liang, S. C. Liu, H. S. Xue, E. Birgersson, J. W. Ho, X. S. Qin, J. Y. Lin, R. J. Ma, T. Liu, Y. L. He, A. M. C. Ng, X. G. Guo, Z. B. He, H. Yan, A. B. Djurišić, Y. Hou, Nature Energy 7, 229-237, 2022.